A financially troubled hospital serving a largely African-American and Caribbean niche of central Brooklyn is planning to declare bankruptcy this week, hospital officials said on Sunday, raising concerns that New York State may force it to close or merge with another institution. The hospital, Interfaith Medical Center, has been in and out of financial trouble for decades, with its survival dependent on infusions of state aid. In difficult economic times, however, Governor Cuomo's administration has not indicated a willingness to continue bailing out failing hospitals.